The phase diagram of agreement, drawn live. Two hundred oscillators tick on the ring; the plot maps their order parameter r against the coupling K. Below the threshold every voice keeps its own time; above it synchrony condenses — a knee, not a slope.
Press sweep and the coupling walks itself up and back down, drawing the curve. Or drag the slider — or drag across the plot — to trace it by hand. Up and down never retrace: the crowd remembers which way it came. Double-click the plot to wipe it and begin again.